Insight into the piezo-photo coupling effect of PbTiO3/CdS composites for piezo-photocatalytic hydrogen production

• Published in: Applied catalysis. B, Environmental Vol. 282; p. 119586
• Main Authors: Huang, Xueyan, Lei, Rui, Yuan, Jie, Gao, Fan, Jiang, Cankun, Feng, Wenhui, Zhuang, Jiandong, Liu, Ping
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2021; Elsevier BV
• Subjects: Coupling; Data analysis; Finite element method; Heterojunctions; Heterostructures; Hydrogen production; Lead titanates; Mathematical models; PbTiO3/CdS; Photocatalysis; Piezo-photo coupling effect; Piezoelectricity; Polarization; Piezoelectricity; Piezo-photo coupling effect; PbTiO3/CdS; Photocatalysis; Hydrogen production
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.119586

[Display omitted] •The shielding effect of the polarization field was confirmed in the PbTiO3/CdS system under illumination alone.•The alternating piezoelectric field is an effective strategy to prevent the electric field from being screened.•The piezo-photocatalytic process leads to higher H2 production performance compare to piezocatalysis or photocatalysis.•The charge transfer mechanism about the piezo-photo coupling effect was proposed. The polarization field with the function in carrier separation has aroused substantial interest. For heterojunction complexes, however, the static polarization field will be inevitably shielded by a large number of carriers. Herein, a novel hybrid consisted of single-domain PbTiO3 coated by CdS particles was selected as a model material to prove that the alternating piezoelectric field induced by periodic stress can destroy shielding effect. After the introduction of alternating piezoelectric potential by using ultrasonication, PbTiO3/CdS-10 % exhibited a much higher H2 production rate by piezo-photocatalysis (849.0 μmol h−1 g−1) than by individual piezocatalysis (400.6 μmol h−1 g−1) or photocatalysis (98.9 μmol h−1 g−1). Furthermore, the finite element simulation shows that PbTiO3/CdS heterostructure has a superior piezoelectric potential difference compare to pure PbTiO3 or pure CdS. Based on data analysis, the mechanism about the piezo-photo coupling effect was proposed, which will provide a reference for the design and development of high-efficiency piezo-photocatalyst.